Loss of cabin pressure.

Attributes
ACN	290028
Time
Date	199412
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : orl
State Reference	FL
Altitude	msl bound lower : 10000 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 210 flight time total : 9000 flight time type : 700
ASRS Report	290028
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp
Experience	flight time last 90 days : 100 flight time total : 18000 flight time type : 500
ASRS Report	290091
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : declared emergency
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

In cruise, at FL270, the flight engineer announced that he could not keep the cabin from climbing. Just previous to this, the flight engineer was working on what we thought to be a pack problem. A loud pop was then heard and the flight engineer tried to keep the cabin from climbing. After announcing that the cabin was climbing unctlably, he said take us down. The captain had already asked for lower and we were given a descent to FL240. While descending to FL240 the captain declared an emergency and set the transponder to 7700. The emergency descent checklist was completed. The remainder of the flight was flown at 10000 ft. At 10000 ft the pressurization system maintained cabin pressure on schedule. Supplemental information from acn 290091: I noticed the cabin pressure was still climbing at 200-300 FPM. While trouble-shooting the problem, we heard a loud 'bang' and the cabin climbed unctlably at 1500-1800 FPM. I advised the captain that the cabin was uncontrollable and that we needed to descend immediately. The captain got a descent to 240 and he declared an emergency, squawked 7700, received a clearance to descend to 10000 ft. The cabin pressure never exceeded 6000 ft and was ctlable at 10000 ft and landed about 20 min late.

Original NASA ASRS Text

Title: LOSS OF CABIN PRESSURE.

Narrative: IN CRUISE, AT FL270, THE FE ANNOUNCED THAT HE COULD NOT KEEP THE CABIN FROM CLBING. JUST PREVIOUS TO THIS, THE FE WAS WORKING ON WHAT WE THOUGHT TO BE A PACK PROB. A LOUD POP WAS THEN HEARD AND THE FE TRIED TO KEEP THE CABIN FROM CLBING. AFTER ANNOUNCING THAT THE CABIN WAS CLBING UNCTLABLY, HE SAID TAKE US DOWN. THE CAPT HAD ALREADY ASKED FOR LOWER AND WE WERE GIVEN A DSCNT TO FL240. WHILE DSNDING TO FL240 THE CAPT DECLARED AN EMER AND SET THE XPONDER TO 7700. THE EMER DSCNT CHKLIST WAS COMPLETED. THE REMAINDER OF THE FLT WAS FLOWN AT 10000 FT. AT 10000 FT THE PRESSURIZATION SYS MAINTAINED CABIN PRESSURE ON SCHEDULE. SUPPLEMENTAL INFO FROM ACN 290091: I NOTICED THE CABIN PRESSURE WAS STILL CLBING AT 200-300 FPM. WHILE TROUBLE-SHOOTING THE PROB, WE HEARD A LOUD 'BANG' AND THE CABIN CLBED UNCTLABLY AT 1500-1800 FPM. I ADVISED THE CAPT THAT THE CABIN WAS UNCTLABLE AND THAT WE NEEDED TO DSND IMMEDIATELY. THE CAPT GOT A DSCNT TO 240 AND HE DECLARED AN EMER, SQUAWKED 7700, RECEIVED A CLRNC TO DSND TO 10000 FT. THE CABIN PRESSURE NEVER EXCEEDED 6000 FT AND WAS CTLABLE AT 10000 FT AND LANDED ABOUT 20 MIN LATE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.